If the option does not exist or does not have a value, then the return value
will be false. This is useful to check whether you need to install an option
and is commonly used during installation of plugin options and to test
whether upgrading is required.

If the option was serialized then it will be unserialized when it is returned.

Any scalar values will be returned as strings. You may coerce the return type of
a given option by registering an {@see 'option_$option'} filter callback.